diff --git a/backend/open_webui/config.py b/backend/open_webui/config.py
index 2576e8e995..8d5b6829dc 100644
--- a/backend/open_webui/config.py
+++ b/backend/open_webui/config.py
@@ -570,6 +570,8 @@ OAUTH_BLOCKED_GROUPS = PersistentConfig(
     os.environ.get("OAUTH_BLOCKED_GROUPS", "[]"),
 )
 
+OAUTH_GROUPS_SEPARATOR = os.environ.get("OAUTH_GROUPS_SEPARATOR", ";")
+
 OAUTH_ROLES_CLAIM = PersistentConfig(
     "OAUTH_ROLES_CLAIM",
     "oauth.roles_claim",
diff --git a/backend/open_webui/utils/oauth.py b/backend/open_webui/utils/oauth.py
index 26706b65f4..392f4cd4bf 100644
--- a/backend/open_webui/utils/oauth.py
+++ b/backend/open_webui/utils/oauth.py
@@ -42,6 +42,7 @@ from open_webui.config import (
     ENABLE_OAUTH_GROUP_MANAGEMENT,
     ENABLE_OAUTH_GROUP_CREATION,
     OAUTH_BLOCKED_GROUPS,
+    OAUTH_GROUPS_SEPARATOR,
     OAUTH_ROLES_CLAIM,
     OAUTH_SUB_CLAIM,
     OAUTH_GROUPS_CLAIM,
@@ -1035,7 +1036,11 @@ class OAuthManager:
             if isinstance(claim_data, list):
                 user_oauth_groups = claim_data
             elif isinstance(claim_data, str):
-                user_oauth_groups = [claim_data]
+                # Split by the configured separator if present
+                if OAUTH_GROUPS_SEPARATOR in claim_data:
+                    user_oauth_groups = claim_data.split(OAUTH_GROUPS_SEPARATOR)
+                else:
+                    user_oauth_groups = [claim_data]
             else:
                 user_oauth_groups = []